Compared to cold hearth melting techniques, vacuum induction melting (VIM) is relatively inexpensive and capable of a high production rate. However, if VIM is the chosen method for amorphous alloy production, there is a need for an effective means of producing clean alloy feedstock (i.e. low oxygen, carbon, nitrogen, other metallic impurities). Currently, graphite is the most common crucible material used to contain melts of Zr-based amorphous alloys. Melts produced in this type of crucible typically contain elevated levels of carbon, especially after repeated recycling due to diffusion of carbon atoms from the graphite-containing crucible into the melts. Similarly, zirconia and alumina both react significantly with most Zr-based BMG compositions and thus crucible containing these materials can often have undesirable results. Thus, contamination remains a challenge.
Thus a need exists to develop a crucible that can be used in VIM and can minimize the contamination of the alloys by the elements of the crucible material.